The Wake Forest University School of Medicine (WFUSM) is an international leader in the use of non-human primates to study human disease. For four decades we have utilized non-human primate models to study the biological basis of diverse disease states, including atherosclerosis, oestopathology, substance abuse, aging, and peripheral nerve injury. Over the past five years, the WFUSM has adapted the functional imaging technique Positron Emission Tomography (PET) to study the neurobiological correlates of behavior in non-human primates. This program incorporates cross-departmental efforts of faculty in the Departments of Radiology, Physiology & Pharmacology, Pathology, Anesthesiology and Neurobiology & Anatomy. The incorporation of PET imaging into behavioral studies of primate models of chronic disease is unique. The rapid growth of the this Program reflects the uniqueness of this approach and the importance of this research to the NIH mission. However, the current PET scanner of the WFUSM for conducting this research is no longer state-of-the-art and lacks the spatial resolution needed to fully maximize the results of our research. For example, cocaine has been shown to result in a higher increase in synaptic dopamine levels in limbic dopaminergic structures (e.g., the nucleus accumbens) relative to structures in the nigrostriatal dopaminergic systems (e.g., caudate/putamen). Therefore, the long term exposure to cocaine in our rhesus monkey self- caudate/putamen. The current PET scanner at WFUSM, which has a spatial resolution of 6 mm in all directions, is not capable of separating these structures and our PET studies currently measure dopamine D2 receptors in the entire basal ganglia complex (caudate, putamen and nucleus accumbens). Therefore, the Specific Aim of this Shared Instrumentation Grant is to enable the purchase of a high resolution primate PET scanner, possessing a spatial resolution of 2 mm in all directions, in order to enhance the research capabilities of this research program.